154 HABITS OF BIRDS. 



reason that the birds in whose nest the cuckoo para- 

 sitically deposites her egg, often, if not always, turn 

 out or destroy their own to make room for hers. 



During the process of hatching, the mother-bird 

 acts as if she knew that, by keeping the eggs all in 

 one position, some would be more favourably treat- 

 ed than others. 



Sheltering of the Young. In rearing tender song- 

 birds taken from their mothers, as is frequently 

 done, before they are fledged, experience proves that 

 warmth is no less indispensable than food ; exposure 

 to cold during the night frequently killing the most 

 healthy nestlings. The mother-birds, well aware 

 of this, are equally assiduous in covering their 

 chicks after they are hatched as they had previously 

 been while sitting on the eggs. Among small birds 

 (Sylvicola, VIEILLOT), accordingly, for several days 

 after her brood has been hatched, the mother sel- 

 dom quits the nest, the male providing the food 

 necessary for her and the little ones, who as yet 

 require but a very small portion. The wren, and 

 other birds which build domed nests, have this ad- 

 ditional protection to prevent the dissipation of 

 their animal heat ; and birds of prey, pigeons, and 

 crows, have but a small number of nestlings to 

 shelter. 



In the case again of poultry, when the newly- 

 hatched birds can run about, the mothers have no 

 little- trouble in sheltering them from the cold, and, 

 even during" the hottest weather, from rain, which 

 proves very injurious in consequence of the cold 

 produced by its evaporation. However much, also, 

 we may admire the ingenuity of birds in some 

 things, and their anxious affection for their young, 

 yet they exhibit in other instances great apparent 

 stupidity ; and maternal affection, so far from sharp- 

 ening their faculties, seems at first rather to blind 

 them, and to cause them to injure and even to kill 

 some of their chickens through awkwardness or in- 



